Use l$\text{'}$H$$pital$\text{'}$s Rule to evaluate $\underset{x0}{lim}\frac{3-3cosx}{7x^2}.$ Then determine the limit using limit laws and commonly known limits$.$

A$.\underset{x0}{lim}\frac{3-3cosx}{7x^2}=\underset{x0}{lim}[\frac{77cosx}{3}]$

B$.\underset{x0}{lim}\frac{3-3cosx}{7x^2}=\underset{x0}{lim}[\frac{3si{n}^{2}x}{7x^2}]$

C$.\underset{x0}{lim}\frac{3-3cosx}{7x^2}=\underset{x0}{lim}[(\frac{sinx}{x})(\frac{sinx}{x})\frac{3}{77cosx}]$

D$.\underset{x0}{lim}\frac{3-3cosx}{7x^2}=\underset{x0}{lim}[(\frac{sinx}{x})\frac{3}{77cosx}]$